Rich wrote:

Moving lots of air wastes water and electricity.

Why do you say that? They use relatively little water - only that which is
evaporated and a bit more if some is bled off.

"Evaporative cooler water use" by Martin Karpiscak and Mary H. Marion at
http://ag.arizona.eduj/pubs/consumer/az9145.pdf cites a survey showing
an average water usage of 7.6 gph, which seems like a lot compared to the
7.6 gpd below. And these things have 1/2 to 1 HP motors.

A Las Vegas homeowner might do better with Sam's portable 797895 Arctic
Breeze cooler mounted inside a house near an open low window and
an exhaust fan in a higher window with a one-way plastic film damper.

You can't recycle the air in the house. You have to get rid of the moist
air as it will not cool.

That's what the exhaust fan does, controlling the indoor RH precisely with
a humidistat, vs a swamp cooler without a humidistat.

Turn on the cooler when the house temp reaches 80 F and turn on the
exhaust fan when the RH reaches 60% to keep the house air at the upper
right corner (80 F and w = 0.012) of the ASHRAE 55-2004 comfort zone.

The 80 F comes from a room temp thermostat.

Your house would be like a steam bath.

I disagree, as do 21,000 ASHRAE comfort survey participants.

The maximum cooling is when the humidity is very low. Once it gets to
30% cooling becomes marginal.

You are thinking about the air outside vs inside the house.

Keeping that house 80 F while evaporating P lb/h of water into C cfm of
outdoor air means 1000P = (91.1-80)(128+C). P = 60C(0.075)(0.012-0.0066)
= 0.0243C makes C = 108 cfm and P = 2.62 lb/h, ie 7.6 gallons per day.
If the house has significant thermal mass (eg a floorslab), we can save
more water and energy by only running the cooler at night.

Why do we need 5000 cfm???

Air-leaky houses with no insulation, poor controls, ignorant owners and
HVAC criminals? :-)

Nick

It's a snap to save energy in this country. As soon as more people
become involved in the basic math of heat transfer and get a gut-level,
as well as intellectual, grasp on how a house works, solution after
solution will appear.
Tom Smith, 1980